Move LTTng-UST buffer ownership from application to consumer

[lttng-tools.git] / src / common / relayd / relayd.c

diff --git a/src/common/relayd/relayd.c b/src/common/relayd/relayd.c
index c883ea5d7f44432ead4ecbc614f8a8abc52686b1..9e10c83e02f7ec583bff72cd5b6d70b42870dca1 100644 (file)
--- a/src/common/relayd/relayd.c
+++ b/src/common/relayd/relayd.c
@@ -90,8 +90,16 @@ static int recv_reply(struct lttcomm_sock *sock, void *data, size_t size)
        DBG3("Relayd waiting for reply of size %ld", size);
 
        ret = sock->ops->recvmsg(sock, data, size, 0);
-       if (ret < 0) {
-               ret = -errno;
+       if (ret <= 0 || ret != size) {
+               if (ret == 0) {
+                       /* Orderly shutdown. */
+                       DBG("Socket %d has performed an orderly shutdown", sock->fd);
+               } else {
+                       DBG("Receiving reply failed on sock %d for size %lu with ret %d",
+                                       sock->fd, size, ret);
+               }
+               /* Always return -1 here and the caller can use errno. */
+               ret = -1;
                goto error;
        }
 
@@ -103,8 +111,8 @@ error:
  * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
  * set session_id of the relayd if we have a successful reply from the relayd.
  *
- * On success, return 0 else a negative value being a lttng_error_code returned
- * from the relayd.
+ * On success, return 0 else a negative value which is either an errno error or
+ * a lttng error code from the relayd.
  */
 int relayd_create_session(struct lttcomm_sock *sock, uint64_t *session_id)
 {
@@ -122,7 +130,7 @@ int relayd_create_session(struct lttcomm_sock *sock, uint64_t *session_id)
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
@@ -228,7 +236,7 @@ int relayd_version_check(struct lttcomm_sock *sock, uint32_t major,
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &msg, sizeof(msg));
        if (ret < 0) {
                goto error;
@@ -319,15 +327,44 @@ int relayd_connect(struct lttcomm_sock *sock)
 
 /*
  * Close relayd socket with an allocated lttcomm_sock.
+ *
+ * If no socket operations are found, simply return 0 meaning that everything
+ * is fine. Without operations, the socket can not possibly be opened or used.
+ * This is possible if the socket was allocated but not created. However, the
+ * caller could simply use it to store a valid file descriptor for instance
+ * passed over a Unix socket and call this to cleanup but still without a valid
+ * ops pointer.
+ *
+ * Return the close returned value. On error, a negative value is usually
+ * returned back from close(2).
  */
 int relayd_close(struct lttcomm_sock *sock)
 {
+       int ret;
+
        /* Code flow error. Safety net. */
        assert(sock);
 
+       /* An invalid fd is fine, return success. */
+       if (sock->fd < 0) {
+               ret = 0;
+               goto end;
+       }
+
        DBG3("Relayd closing socket %d", sock->fd);
 
-       return sock->ops->close(sock);
+       if (sock->ops) {
+               ret = sock->ops->close(sock);
+       } else {
+               /* Default call if no specific ops found. */
+               ret = close(sock->fd);
+               if (ret < 0) {
+                       PERROR("relayd_close default close");
+               }
+       }
+
+end:
+       return ret;
 }
 
 /*
@@ -389,7 +426,7 @@ int relayd_send_close_stream(struct lttcomm_sock *sock, uint64_t stream_id,
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
@@ -439,7 +476,7 @@ int relayd_data_pending(struct lttcomm_sock *sock, uint64_t stream_id,
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
@@ -485,7 +522,7 @@ int relayd_quiescent_control(struct lttcomm_sock *sock,
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
@@ -529,7 +566,7 @@ int relayd_begin_data_pending(struct lttcomm_sock *sock, uint64_t id)
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
@@ -576,7 +613,7 @@ int relayd_end_data_pending(struct lttcomm_sock *sock, uint64_t id,
                goto error;
        }
 
-       /* Recevie response */
+       /* Receive response */
        ret = recv_reply(sock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;